1. Field of the Invention
The invention relates to a workpiece support apparatus.
2. Related Art
In general, when a plate-shaped workpiece is cut by a laser machining apparatus, a machined portion of the workpiece is irradiated by a laser beam from a nozzle of a machining head, while assistant gas is sprayed from the nozzle. In this instance, a material of the machined portion is melted or evaporated by the laser beam, and is removed by the assistant gas. For this reason, the workpiece to be machined is supported by, for example, a pin support type of a workpiece support apparatus so that a member for supporting the workpiece is not irradiated by the laser beam.
As the workpiece support apparatus, for example, a workpiece receiving table is disclosed in Patent Document 1 (JP-U-62-077688), in which the workpiece to be cut by the laser beam is supported by a plurality of support pins arranged in a matrix pattern. The workpiece receiving table includes an electromagnet that selectively attracts and pulls down the respective support pins arranged to be urged in an upward direction at a machining position of the workpiece.
According to the workpiece receiving table of Patent Document 1, when the workpiece is cut by the laser beam, if the support pin exists on or near a cut line of the workpiece, the support pin is attracted and moved downward by the electromagnet. In this way, the support pin is prevented from being melted by the laser beam.
However, according to the workpiece receiving table disclosed in Patent Document 1, since the electromagnet attracting the support pin is provided at the machining position of the workpiece, the selective pull-down of the support pin is only possible after introduction of the workpiece to the machining position is completed. For this reason, a cycle time required to cut the workpiece includes a time required for the selective pull-down of the support pin which is carried out after the introduction of the workpiece to the machining position is completed, and thus the cycle time is extended to that extent.